Premixes and method of preparing adhesives ad caulks from premixes

ABSTRACT

Sets of fluid premixes useful for adhesives and caulks are provided. Also provided are methods of providing adhesive lines and a caulk lines using the sets of premixes. Further provided are ranges of adhesives and caulks based on the adhesive and caulk lines. Utilizing these methods the manufacturer, seller, or user can to adjust the adhesive or caulk at the point of manufacture, sale, or use to suit the processing and end-use conditions, in addition to the other benefits offered by delayed product differentiation.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional ApplicationsSer. Nos. 60/183,655 filed Feb. 18, 2000, 60/183,656 filed Feb. 18,2000, and 60/247,639 filed Nov. 10, 2000.

BACKGROUND OF THE INVENTION Field of the Invention

[0002] This invention relates to sets of binder premixes methods ofpreparing adhesives and caulks from the sets of premixes, and to methodsof preparing ranges of adhesives and caulks from sets of the premixes.

[0003] In co-pending U.S. patent applications Ser. Nos. 60/183,655;60/183,656; and 60/247,639; we describe prepaints and method of makingpaints from these prepaints employing delayed product differentiation.The use of sets of premixed ingredients or raw materials as described inthese applications may be extended to the preparation of adhesives.

[0004] Adhesive formulating involves selecting and admixing appropriateadhesive ingredients in the correct proportions to provide an adhesivewith specific processing and handling properties, as well as the desiredfinal dry adhesive film properties. The major ingredients of manyadhesives are the binder, optional tackifier, and a fluid medium if theformulation is not presented neat, the fluid medium is, water if theadhesive is a water-borne adhesive, or solvent if the adhesive is asolvent-borne adhesive. Common optional ingredients include defoamers,coalescents, plasticizers, thickeners, rheology modifiers, solvents,driers, anti-skinning agents, surfactants, mildewcides, biocides,crosslinkers, white opacifying pigments, extender pigments, colorants,and dispersants. After the fluid adhesive is formulated and applied to asurface, the adhesive dries by evaporation of the water and/or thesolvent, with or without the application of heat or radiation, and thebinder forms a film containing therein the pigment and the extenderparticles, if any.

[0005] Formulating adhesives is complex—it is not simply a matter ofmixing a few ingredients in different ratios. Rather, it involves theselection and mixing of different ingredients in different ratiosdepending on the type of adhesive desired. This requires manufacturersto store many different ingredients and change ingredients duringmanufacture depending on the specific adhesive type being prepared.

[0006] Furthermore, it requires those involved in the supply chain, andin particular, adhesive retailers, to carry a large inventory ofadhesives in order to offer a range of adhesives, such as various peellevels, viscosity levels, adhesion levels, removability levels andrepositionability levels.

[0007] From the perspective of number of ingredients required,formulating an adhesive is less complex than formulating anarchitectural paint. However, the processing and end-use applications ofan adhesive may involve a broader range of conditions than are typicallyexperienced during the application of an architectural paint. Forexample, an adhesive may be applied at varying shear rates depending onthe processing equipment used (for example, extrusion, gravure and mayerrod type applicators, roller and die coating, and the like) and usedover a broad range of temperatures (for example, from less than 0° C. inlow-temperature or all-temperature applications to greater than 40° C.in some packaging applications).

[0008] Therefore, it would be desirable to make adhesives, either at arelatively large-scale industrial plant or at a relativelysmaller-scale, point-of-application, point-of-sale, or point-of-uselocation using a limited number of ingredients, to prepare all of thesedifferent adhesives, thus, minimizing the number and type of ingredientsrequired to make a range of adhesives. Thus, it would be useful to havea system that would permit the manufacturer, seller, or user to adjustthe adhesive at the point of manufacture, sale, or application, to suitthe processing and end-use conditions.

SUMMARY OF THE INVENTION

[0009] The present invention provides sets of fluid premixes binder, oneor more adhesive lines, and a range of adhesives. A “fluid,” as usedherein, means any material that flows, including liquids, flowablepowders, and viscous, amorphous solids. As used herein, premixes are“mutually compatible” if the adhesives formed by admixing the premixesdo not evidence signs of colloidal instability such as flocculation.Preferably, the adhesives formed from the premixes exhibit less than 5grams of residue, such as gel and grit, per liter of adhesive when theadhesive is passed through a 325 mesh screen, more preferably less than1 gram of residue per liter. Preferably, the premixes exhibit less than5 grams of residue, such as gel and grit, per liter of premix whenpassed through a 325 mesh screen, more preferably less than 1 gram ofresidue per liter of premix. If the premixes and optional additivesincluded to enhance specific adhesive properties are fully compatible,i.e., they can be blended at any ratio without inducing colloidalinstability, then they can be blended in any combination falling withinthe formulation space needed to achieve the desired property profile inthe final adhesive. It is sufficient, however, if the premixes andoptional additives can be blended at desired ratios without inducingcolloidal instability to achieve the desired property profile in therange of adhesives. As used herein, “adhesive” is used in a broad senseto include all types of adhesives including neat, water-borne, andsolvent-borne adhesives, including pressure sensitive adhesive andnon-pressure sensitive adhesives. Pressure sensitive adhesives (“PSAs”)that may be made by the method of the invention include any conventionalPSAs including, without limitation, hot melt adhesives, solvent-basedrubber adhesives, styrene-butadiene rubber emulsion adhesives, andacrylic adhesives. Such PSAs are employed in a number of applications,for example in tape and label applications. This definition of“adhesives” is intended to include products conventionally known assealants, joint cements, plasters, pastes, ceramic tile adhesives,caulks, and like building adhesives.

[0010] An “adhesive line”, as used herein, includes at least twodifferent adhesives which offer properties which differ materially fromeach other in at least one observable property, such as adhesion tocertain substrates, viscosity, removability, and repositionability.Adhesive manufacturers and retailers typically offer a range ofadhesives, the range including at least two adhesive lines. By “therange including at least two adhesive lines,” as used herein, is meantthat the discrete elected levels of the observable property defining afirst adhesive line are combined with the discrete elected levels of theobservable property defining a second adhesive line, etc. to define theadhesives in the range of adhesives. For example, preparing a range ofadhesives including five adhesive lines may require preparing adhesivesencompassing two peel levels, two viscosity levels, two adhesion levels,two removability levels, two repositionability levels, and preferablyall combinations thereof. Thus, 32 different adhesive formulations(2×2×2×2×2) may be needed. Also encompassed, however, is a range ofadhesives in which a certain number of adhesive lines or premixes,including up to as high as 10-60% of the total number, are omitted, forexample, for commercial reasons or for stability reasons.

[0011] A set of different, but mutually compatible, fluid adhesivebinder premixes, sufficient to formulate at least one adhesive line,comprises (a) at least one premix comprising at least one polymericbinder having a peel of less than about 20 ounces/inch, a tack of lessthan about 300 grams, and a shear of greater than about 50 hours; (b) atleast one premix comprising at least one polymeric binder having a peelof less than about 20 to about 50 ounces/inch, a tack of about 300 toabout 500 grams, and a shear of about 5 to about 50 hours, and (c) atleast one premix comprising at least one polymeric binder having a peelof greater than about 50 ounces/inch, a tack of greater than about 500grams, and a shear of less than about 10 hours. Preferably, the numberof premixes is from 3 to 15.

[0012] The present invention also provides an adhesive composition whichcomprises the set of premixes as set forth above, and optionally atleast one additional ingredient selected from the group consisting of atackifier, a thickener, and a crosslinker.

[0013] Optionally, at least one of the premixes further comprises atleast one optional additive selected from the group consisting of atackifier, a plasticizer, a thickener and a crosslinker.

[0014] Also provided is a method of formulating at least one adhesiveline, which method comprises the steps of:

[0015] (a) selecting a set of different, but mutually compatible, fluidadhesive binder premixes, comprising:

[0016] (i) at least one premix comprising at least one polymeric binderhaving a peel of less than about 20 ounces/inch, a Polyken tack of lessthan about 300 grams and a shear of greater than about 50 hours; (ii) atleast one premix comprising at least one polymeric binder having a peelof less than about 20 to about 50 ounces/inch, a Polyken tack of about300 to about 500 grams, and a shear of about 5 to about 50 hours; and(iii) at least one premix comprising at least one polymeric binderhaving a peel of greater than about 50 ounces/inch, a Polyken tack ofgreater than about 500 grams, and a shear of less than about 10 hours;and

[0017] (b) dispensing or predetermined amount of each of the premixesinto containers or applicators to form the adhesive line. Preferably,the number of premixes is from 3 to 5.

[0018] Further provided is a method of providing a range of adhesives,the range comprising at least two adhesive lines, which method comprisesthe steps of:

[0019] (a) selecting a set of different, but mutually compatible, fluidadhesive binder premixes, which set comprises (i) at least one premixcomprising at least one polymeric binder having a peel of less thanabout 20 ounces/inch, a Polyken tack of less than about 300 grams, and ashear of greater than about 50 hours, (ii) at least one premixcomprising at least one polymeric binder having a peel of less thanabout 20 to about 50 ounces/inch, a Polyken tack of about 300 to about500 grams, and a shear of about 5 to about 50 hours, (iii) at least onepremix comprising at least one polymeric binder having a peel of greaterthan about 50 ounces/inch, a Polyken tack of greater than about 500grams, and a shear of less than about 10 hours; and (iv) at least oneadditional different premix selected from (i), (ii), or (iii); and

[0020] (b) dispensing a predetermined amount of each of the premixesinto containers or applicator[s] to form the adhesive lines. Preferably,the number of premixes is from 4 to 15.

[0021] The methods herein may further comprise the step(s) of providingat least one tackifier, at least one thickener, at least onecrosslinker, or combinations thereof. Predetermined amounts of thetackifier, the thickener; and or crosslinker are dispensed intocontainers or the applicator(s).

[0022] Also provided is a different set of premixes sufficient to format least one different adhesive line, which set comprises at least twodifferent, but mutually compatible, fluid adhesive binder premixesselected from the group consisting of (a) at least one premix comprisingat least one curable prepolymer that forms a polymeric binder that has aTg of about −70° C. to about 0° C. when cured; (b) at least one fluidpremix comprising at least one curable prepolymer that forms a polymericbinder which has a Tg of about −10° C. to about 70° C. when cured; (c)at least one premix comprising at least one polymeric binder which has aTg of about 0° C. to about 30° C.; (d) at least one premix comprising atleast one polymeric binder which has a Tg of about −15° C. to about 15°C.; and (e) at least one premix comprising at least one polymeric binderwhich has a Tg of about −70° C. to about 0° C.

[0023] Also provided is a method of providing at least one adhesiveline, which method comprises the steps of (a) providing a set ofdifferent, but mutually compatible, fluid adhesive binder premixescomprising at least two premixes selected from the group consisting of(i) at least one premix comprising at least one curable prepolymer thathas a Tg of about −70° C. to about 0° C. when cured; (ii) at least onepremix comprising at least one curable prepolymer that has a Tg of about−10° C. to about 70° C. when cured; (iii) at least one premix comprisingat least one polymeric binder having a Tg of about 0° C. to about 30°C.; (iv) at least one premix comprising at least one polymeric binderhaving a Tg of about −15° C. to about 15° C.; and (v) at least onepremix comprising at least one polymeric binder having a Tg of about−70° C. to about 0° C.; and (b) dispensing a predetermined amount ofeach of the premixes into containers or an applicator to form the oneadhesive line.

[0024] Further provided is a method of providing a range of adhesives,the range comprising at least two adhesive lines, which method comprisesthe steps of:

[0025] (a) providing a set of different, but mutually compatible, fluidadhesive binder premixes comprising at least three premixes selectedfrom the group consisting of (i) at least one premix comprising at leastone curable prepolymer that has a Tg of about −70° C. to about 0° C.when cured; (ii) at least one premix comprising at least one curableprepolymer that has a Tg of about −10° C. to about 70° C. when cured;(iii) at least one premix comprising at least one polymeric binderhaving a Tg of about 0° C. to about 30° C.; (iv) at least one premixcomprising at least one polymeric binder having a Tg of about −15° C. toabout 15° C.; (v) at least one premix comprising at least one polymericbinder having a Tg of about −70° C. to about 0° C.; and (vi) at leastone additional different premix selected from premixes (i), (ii), (iii),(iv), and (v); or (b) dispensing a predetermined amount of each of thepremixes into containers or applicators to form the adhesive lines.

[0026] The methods herein may further comprising the step(s) of addingmaterials that enhance the application or final performance of theadhesive, such as tackifiers, plasticizers, thickeners, crosslinkers,and mixtures thereof.

[0027] Caulks are like adhesives and sealants in that they are based onsoft polymers. Many caulks are also like paint in that they can befilled with pigment and extender. Caulks are differentiated by theirhigher solids content and higher viscosity and their use to fill andseal cracks, joints, and the like.

[0028] If one adhesive line is desired, i.e., if one key property is tobe varied (for example, peel, viscosity, adhesion, removability, orrepositionability), then the complete adhesive line can be made from oneeach of premixes (i), (ii), and (iii) which are described above oralternatively from at least two of (a) to (e) which are described above.

[0029] If a range of adhesives including two adhesives lines is desired,i.e., if two key properties are varied (for example, two propertiesselected from peel, viscosity, adhesion, removability, andrepositionability), then the range of adhesives may be made from atleast one each of premixes (i) to (iii) and least one additional,premixes but different selected from premixes (i) to (iii) oralternatively, from at least two of premixes (a) to (e) described aboveand at least one additional different premix selected from premixes (a)to (e) described above depending on which key properties are to bevaried.

[0030] If a range of adhesives including three adhesive lines isdesired, i.e., if three key properties are to be varied (for example,three properties selected from peel, viscosity, adhesion, removability,and repositionability), then the range of adhesives can be made from atleast one each of premix (i), premix (ii), and premix (iii) and at leasttwo additional different premixes selected from (i), (ii), or (iii) oralternatively at least one each of premixes (a) to (e) and at least twoadditional different premixes selected from (a) to (e), depending onwhich key properties are to be varied.

[0031] If a range of adhesives including four adhesive lines is desired,i.e., if four key properties are to be varied (for example, fourproperties selected from peel, viscosity, adhesion, removability andrepositionability), then the range of adhesives can be made from atleast one each of premix (i), premix (ii), and premix (iii) and at leastthree additional different premixes selected from (i) to (iii),depending on which key properties are to be varied.

[0032] This technique may be continued to vary as many additional keyproperties as desired.

[0033] By “additional premix selected from the group consisting of (i),(ii), and (iii)” is meant an adhesive binder premix which is differentfrom adhesive premixes (i), (ii), or (iii), respectively, but whichotherwise meets the limitations associated with premixes (i), (ii), and(iii). By “additional premixes selected from the group consisting of(a), (b), (c), (d), and (e)” is meant herein an adhesive binder premixdifferent from premix (a), (b), (c), (d), or (e), respectively, butotherwise meeting the limitations associated with premix (a), (b), (c),(d) and (e).

[0034] In each of the above embodiments, the premixes are selected tocover a wide formulation space so that the desired final adhesiveproperties lie within the blend space defined by the premixes at theextremes. In many cases, the premixes will not themselves be practicaladhesives, but by pushing the premixes to these extremes one canmaximize the blend space available for the adhesive system. When thepremixes, additives, and colorants are all fully compatible, they can beblended at the desired ratios to achieve the desired adhesive line(s)and range of adhesives without inducing colloidal instability.

[0035] This technique is similar to the design principles used instatistical experimental design and analysis of mixture componentdesigns; however, instead of designing a mixture space to explore theresponse surface within it, one is designing the boundaries of themixture space to maximize the flexibility of the adhesive system. Thekey to success is to have mutual compatibility of the individualingredients and premixes across the mixture space.

[0036] Adhesive properties can be predicted in a number of ways. Oneapproach is to develop response surface models of the blend space usingstandard Mixture Component experimental design statistical tools. Thesesimple statistical models can then be used by a linear optimizationprogram, by a massive grid search, or by a graphical analysis tool.Another approach is to simply use empirical methods to determine whichblends are needed for specific adhesive lines and then incorporate thosesimple empirical recipes in the adhesive-making machine software.

[0037] An extension of this techniques is to have the adhesive machineautomatically pretest certain key properties (e.g. viscosity, adhesionto certain substrates, peel, tack, shear) and make minor adjustmentsduring the formulating of the adhesives from the premixes. Havingfeedback loops in the adhesive machine can provide more precise matchingof color, adhesion, peel strength, tack, shear strength, and viscositytargets.

[0038] It is preferred that the all fluid premixes employed herein havethe same or similar viscosities to aid in mixing. Viscosity fluctuationin the final adhesive formulation is expected to be reduced because ofthe prior equilibration of ingredients in the premixes.

[0039] The premixes are formulated to maximize the flexibility ofadhesive manufacturing. Rather than purchasing individual adhesiveingredients, adhesive manufacturers, and even buyers at point-of-saleand point-of-use (home improvement stores, building product departments,and contractors), can purchase the set of premixes needed to prepare adesired range of adhesives. These sets of premixes will contain at leastone each of premixes (i), (ii) and (iii) and possibly additionalpremixes depending upon the formulating flexibility desired. Optionally,the above premixes are mixed with an additional premix which includes atleast one colorant such as a colored pigment or dye.

[0040] The sets and methods of the invention can be used for caulks.

[0041] Binder selection is a major factor in producing a caulk that hasthe desired set of properties. Those skilled in the art readilyrecognize that binder characteristics such as solids level, monomerselection, molecular weight, Tg modules and many other factors influencethe properties of the caulk. Those skilled in the art also qualitativelyrecognize how to control these characteristics to obtain the desiredcaulk properties. Such properties include the balance between tensilestrength vs. elongation/flexibility, adhesion, surface tack, channelcracking, clarity, yellowing, shrinkage, and cost. While a quantitativerelationship between binder characteristics and properties is difficultto obtain, those skilled in the art can readily select appropriatebinders for use in the binder premixes to produce desired caulkproperties.

[0042] In the caulk embodiment, the set comprises (a) at least one caulkbinder premix comprising at least one polymeric binder which has a Tg ofless than about 0° C.; (b) at least one binder premix comprising atleast one polymeric binder which has a Tg of less than about 25° C.; and(c) optionally, at least one extender premix comprising at least oneextender; wherein the premixes have a solids content of at least about50% by weight.

[0043] Also provided is a method of forming at least one caulk line,which method comprises the steps of:

[0044] (a) providing a set of different, but mutually compatible, fluidcaulk binder premixes sufficient to form at least one caulk line, whichset comprises (i) at least one binder premix comprising at least onepolymeric binder which has a Tg of less than about 0° C.; (ii) at leastone binder premix comprising at least one polymeric binder which has aTg of less than 25° C.; and (iii) optionally, at least one extenderpremix comprising at least one extender; wherein the premixes have asolids content at the least about 50% by weight; and

[0045] (b) dispensing a predetermined amount of each premix intocontainers or applicator(s) to form at least one caulk line.

[0046] The extender premix may further comprise at least one opacifyingpigment. Alternatively or additionally, the set of caulk premixes mayfurther comprise at least one fluid mutually compatible premix,comprising at least one opacifying pigment.

[0047] The methods herein may further comprise the step of mixing theadhesive or caulk binder premixes before, while, or after they aredispensed into the containers. The methods may further comprise the stepof mixing these premixes before or while they are dispensed into theapplicator(s). The methods may further include the step of adjusting theviscosity of these premixes before, while, or after they are dispensedinto the containers or before or while they are dispensed into theapplicator(s). The methods herein may be carried out continuously at amanufacturing facility, at a distributor, at a point-of-sale, or at apoint-of-use. In addition, the methods may be controlled by a computer.By “additional premixes [“a”, “b”, or “c”] is meant a caulk premixdifferent from the caulk binder premixes (a) and (b) and the caulkextender premix (c), respectively, but otherwise meeting the limitationsassociated with the caulk premixes (a), (b) and (c).

[0048] While exemplified with a pressure sensitive adhesive and a caulk,the present methods are not limited to preparing only pressure sensitiveadhesive or caulks per se but may also be extended to the preparation ofany water-borne or solvent-borne adhesive, sealant, caulk or relatedbuilding product. The industries and the market segments where adhesivesand related products produced by the present methods can be used includeadhesives used for construction, primary wood bonding, furniture, landtransportation-OEM, automotive aftermarket, aerospace,electrical/electronic, appliances, packaging, bookbinding, textile,footwear, pressure-sensitive abrasives, friction materials, foundry,consumer, aerosol, medical, dental, miscellaneous product assembly, andthe like.

DETAILED DESCRIPTION OF THE INVENTION

[0049] The premixes herein each contain a polymeric binder havingspecific properties. Polymeric binders are polymers or prepolymers whichform the primary film of the adhesive. Binders bind the pigment, ifpresent, and/or extenders and provide the required adhesive flow. Thebinders selected for the premix will depend upon the final use of theformulated adhesive.

[0050] Suitable polymeric binders include water-borne and solvent-bornenatural and synthetic polymers, including but not limited to,homopolymers, copolymers or terpolymers such as acrylic and/ormethacrylic polymers, polyvinyl acetate, polyvinyl alcohol,styrene-acrylic copolymers, styrene-butadiene copolymers, vinylacetate-acrylic copolymers, ethylene-vinyl acetate copolymers, vinylacetate-vinyl versatate copolymers, vinyl acetate-vinyl maleatecopolymers, vinyl acetate-vinyl chloride-acrylic terpolymers,ethylene-vinyl acetate-acrylic terpolymers, polyurethane, polyvinylbutyral, structural acrylic polymers, anaerobic, cyanoacrylate polymers,polyvinyl chloride, polyvinylidene chloride, polyethylene,ethylene-vinyl acetate copolymers, polypropylene, ethylene/acrylic acidcopolymer, ethylene/methyl acrylate copolymers, irradiated polyethylene,polyamide, polyester, epoxy, phenolic, amino, furan, polyimides, naturalrubber, styrene copolymers and terpolymers, non-block, styrenic blockcopolymers, neoprene, nitrile rubber, butylene, polybutene,ethylene-propylene-diene rubbers, rubber silicone, animal glue, caseins,starch and wheat flours, dextrins, cellulose, bitumen, rosin, lignin,silicate, styrene-butadiene rubber, styrene-butadiene,acrylonitrilebutadiene-styrene, halo-diene, and the like. The polymersor prepolymers may optionally contain up to about 10% by weight of afunctional monomer, for example, but not limited to, carboxylic acid,phosphate, sulfate, sulfonate, and amide monomers and combinationsthereof, non-functional monomers, and mixtures thereof. The polymericbinders are preferably water-borne latex polymers.

[0051] With the premixes, it is optional to include minor amounts, i.e.,less than about 20% by weight, based on the total weight of thepremixes, of conventional adhesive additives such as tackifiers,plasticizers, crosslinkers, thickeners, acids, bases, defoamers,coalescents, cosolvents, dispersing resins, mildewcides, biocides,antifreeze agents, opacifying pigments, extender pigments, colorants,glass and polymeric beads and the like. These additives must becompatible with the other adhesive ingredients in the premix and thepremixes employed in formulating the adhesive lines. These optionalingredients may be added separately or added to the premixes. In theexamples, the tackifier, crosslinker, and/or thickener are included asseparate ingredients rather than being incorporated into the premixes.

[0052] The properties of tack, peel strength, and shear resistance,which are frequently mutually exclusive properties, may be highlyimportant in tailoring an adhesive composition that is suitable for aparticular application. Tack is generally a measure of viscous flowunder conditions of fast strain rates and low stress magnitudes. Peelstrength is a measure of resistance to flow at intermediate strain ratesand moderate to high stress magnitudes, as well as the cohesive strengthof the adhesive. Shear resistance is a measure of resistance to flow atintermediate stress magnitudes.

[0053] Polymeric additives, such as tackifiers and plasticizers, may beadded to modify the properties of the adhesive including, for example,the viscoelastic behavior of the finished adhesive. The particularpolymeric additive selected may vary depending, for example, on theadhesive involved and the modification sought.

[0054] Generally speaking, to enhance the performance characteristics ofthe adhesive the tackifier should possess a certain range of propertieswith respect to the adhesive to which it is added. For example, thetackifier should generally have a lower molecular weight than thepolymer of the adhesive. In addition, the tackifier should generallyhave a glass transition temperature (Tg) higher than that of theadhesive's polymer. The softening temperature of the tackifier shouldgenerally be higher than that of the adhesive's polymer, and thetackifier should generally have a minimum degree of compatibility withthe adhesive's polymer. Suitable tackifiers include dispersed and solidgrade tackifiers such as rosin esters, rosin acids, and hydrocarbonresins including aliphatic and aromatic resins', and the like.

[0055] Plasticizers may be added to an adhesive composition, forexample, to increase its workability, flexibility, and/ordistensibility. They are molecules that are smaller than the polymericbinder molecules present in the adhesive system. Depending upon theinvolved adhesive system, the addition of a plasticizer may lower themelt viscosity, elastic modulus, and glass transition temperature(T_(g)) of the overall system. Plasticizers may also be added to polymerformulations to increase flexibility by promoting bond formation betweenthe polymer molecules and the plasticizer rather than between thepolymer molecules themselves. The plasticizer molecules separate thelarger polymeric chains of the binder and reduce the attractive forcesbetween them and act as a lubricant. In doing so, the plasticizer mayalso increase the specific volume and change the index of refraction ofthe resulting adhesive composition. The addition of the plasticizer mayalso increase the viscosity of the adhesive composition.

[0056] Suitable crosslinkers include multivalent metal such as zinc,magnesium, aluminum, calcium, iron, zirconium, and the like.

[0057] Suitable opacifying pigments include titanium dioxide (TiO₂) or acombination of titanium dioxide and auxiliary hiding pigments such asvoided latex polymer particles, zinc oxide, lead oxide, syntheticpolymer pigments, and mixtures thereof. Rutile and anatase grades oftitanium dioxide are suitable for use herein. Rutile titanium dioxide ispreferred. The surface of these titanium dioxides may be treated withvarious organic and/or inorganic surface treatments, e.g., as the oxidesof silica, alumina, and zirconia. Fumed titanium oxide is also usefulherein.

[0058] The voided latex particles useful herein have a particle sizediameter of about 100 nm to about 2,500 nm and a void fraction of about10% to about 75%. Preferably, the voided latex particles have a particlesize of about 500 nm to about 1,100 nm. The voided latex particles haveat least one void but may have multiple voids, non-spherical voids,interconnected voids, voids having channels connected to the outside ofthe particles, and structures described as vesiculated and sponge-like.Preferably, they have a single void. The voided latex particles have aglass transition temperature (Tg) of at least about 20° C., preferablyat least about 50° C. The higher the glass transition temperature, theharder the particle is and the less likely it is to collapse. If thevoided latex particles collapse, they are unable to contribute tohiding. The voided latex particles may be prepared by conventionalpolymerization processes known in the art, such as those disclosed inU.S. Pat. No. 3,784,391, U.S. Pat. No. 4,798,691, U.S. Pat. No.4,908,271, U.S. Pat. No. 4,972,000, U.S. Pat. No. 5,041,464, U.S. Pat.No. 5,157,084, U.S. Pat. No. 5,216,044 and U.S. Pat. No. 6,020,435, aswell as Japanese Patent Applications 60/223,873, 61/62510, 61/66710,61/86941, 62/127336, 62/156387, 01/185311, and 02/140272. Preferably,the voided latex particles are prepared according to U.S. Pat. No.4,427,836, U.S. Pat. No. 4,469,825, U.S. Pat. No. 4,594,363, U.S. Pat.No. 4,880,842, U.S. Pat. No. 5,494,971 and U.S. Pat. No. 6,020,435.

[0059] Suitable extender pigments for use herein include barium sulfate(about 1 to about 15 microns), Blanc Fixe (about 0.5 to about 5microns), calcium carbonate (about 0.05 to about 35 microns), silica(about 0.001 to about 14 microns), magnesium silicate (about 0.5 toabout 15 microns), aluminum silicate (about 0.2 to about 5 microns),mica, bentonite, magnesium alumino-silicate, fumed alumina, colloidalattapulgite, synthetic amorphous sodium alumino-silicate, sodiumpotassium alumino-silicate, and the like.

[0060] Thickener is a general term which includes any material added toan adhesive to modify its rheological profile. Preferred thickeners areassociative thickeners. Suitable thickeners for use herein includepolyvinyl alcohol (PVA), hydrophobically-modified, alkali-solubleemulsions known in the art as HASE emulsions, alkali-soluble oralkali-swellable emulsions known in the art as ASE emulsions,hydrophobically-modified ethylene oxide-urethane polymers known in theart as HEUR thickeners, and cellulosic thickeners such as hydroxymethylcellulose (HMC), hydroxyethyl cellulose (HEC), hydrophobically-modifiedhydroxyethyl cellulose (HMHEC), sodium carboxymethyl cellulose (SCMC),sodium carboxymethyl 2-hydroxyethyl cellulose, 2-hydroxypropyl methylcellulose, 2-hydroxyethyl methyl cellulose, 2-hydroxybutyl methylcellulose, 2-hydroxyethyl ethyl cellulose, 2-hydoxypropyl cellulose, andthe like. Also useful as thickeners are fumed silica, attapulgite clayand other types of clay, titanate chelating agents, and the like.

[0061] Suitable dispersants for use herein include non-ionic, anionic,and cationic dispersants such as 2-amino 2-methyl 1-propanol (AMP),dimethyl amino ethanol (DMAE), potassium tripolyphosphate (KTPP),trisodium polyphosphate (TSPP), citric acid and other carboxylic acids,and the like. Anionic polymers such as homopolymers and copolymers basedon polycarboxylic acids, including those that have beenhydrophobically-modified or hydrophilically-modified, e.g., polyacrylicacid or polymethacrylic acid or maleic anhydride with various monomerssuch as styrene, acrylate or methacrylate, diisobutylene, and otherhydrophilic or hydrophobic comonomers are also suitable for use asdispersants, further including the salts of the aforementioneddispersants, and mixtures thereof.

[0062] Suitable defoamers include acetylenic diols, silicone-based andmineral oil-based defoamers, and the like.

[0063] Suitable coalescents, plasticizers, and other optional solventsinclude ethylene glycol, propylene glycol, hexylene glycol,2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TEXANOL™), glycolethers, mineral spirits, methyl carbitol, butyl carbitol, phthalates,adipates, and the like.

[0064] Suitable mildewcides and biocides include zinc oxide,isothiazolones, triazoles, and the like.

[0065] Suitable surfactants include cationic, anionic, and non-ionicsurfactants.

[0066] In order to minimize the number of adhesive ingredients needed toprepare a range of adhesives, one needs to consider the extremes of thekey properties required for the range of adhesives and formulateadhesive premixes which are capable of being blended in variouscombinations to provide the key properties required at the extremevalues and at intermediate points as well. Specific properties may alsobe improved by including adhesive additives which enhance the desiredproperty.

[0067] All ranges disclosed herein are inclusive and the minimums andmaximums of the nested ranges are combinable. The measurement of tack ismade in accordance with PSTC Standard Tack Test at a rate of 12inches/minute. The measurement of peel is made in accordance with PSTCStandard Peel Test on a Polyken tester. The measurement of shear is madeon a test sample with a 1 square inch overlap with a 1 kg weight understatic shear at a temperature of 55-80° F. All of the above measurementsare made using a coating thickness of 0.9-1.1 mils. The glass transitiontemperature (“Tg”) is measured via differential scanning calorimetry ata rate of 20° C./minute.

EXAMPLES Example 1

[0068] Preparation of Adhesive Binder Premixes

[0069] Premix 1 is prepared by mixing 100 grams of an acrylic pressuresensitive polymer (N-619 available from Rohm and Haas Company,Philadelphia, Pa.) with 0.5 grams of a standard commercial non-ionic oranionic wetting agent, 1.0 grams of an ethoxylated phenol mechanicalstabilizer, and 0.5 grams of a standard defoamer. The pH is adjusted toabove 8.0 with ammonia.

[0070] Premix 2 is prepared by mixing 100 grams of an acrylic pressuresensitive polymer (N-580 available from Rohm and Haas Company,Philadelphia, Pa.) with 0.5 grams of a standard commercial non-ionic oranionic wetting agent, 1.0 gram of an ethoxylated phenol mechanicalstabilizer, and 0.5 grams of a standard defoamer. The pH is adjusted toabove 8.0 with ammonia.

[0071] Premix 3 is prepared by mixing 100 grams of an acrylic pressuresensitive polymer (N-1031 available from Rohm and Haas Company,Philadelphia, Pa.) with 0.5 grams of a standard commercial non-ionic oranionic wetting agent, 1.0 grams of an ethoxylated phenol mechanicalstabilizer, and 0.5 grams of a standard defoamer. The pH is adjusted toabove 8.0 with ammonia.

Example 2

[0072] Preparation of Adhesives

[0073] Binders 1, 2, and 3 may be combined in various ratios along withvarious levels of dispersed tackifier and crosslinker to produceadhesives having characteristics suitable for pressure sensitiveapplications such as tape and label applications pressure sensitiveadhesives (PSAs). The adhesives having low viscosities can be appliedvia gravure and Mayer rod-type applicators. The adhesives having higherviscosities are suitable for roller and die coaters.

[0074] The thickener is a HASE thickener (Acrysol TT-6 15 available fromRohm and Haas Company, Philadelphia, Pa.). The tackifier is a dispersedrosin ester, rosin acid, or a hydrocarbon. The crosslinker ismultivalent metallic type.

[0075] The formulation of the adhesive premixes is shown in thefollowing table. The ingredient levels are in grams. Adhesive TypeGeneral Remov- Polyolefin General General Purpose General Repo- Repo-Remov- Remov- Remov- able Ingred- Adhesion Polyolefin Purpose PurposeHigh Purpose sition- sition- able able able High ients ** Adhesion LowPeel Low Peel Peel** High Peel able able Low Peel Low Peel High PeelPeel Premix 50-60 50-60 — — 70-80   70-80 20-30 20-30 — — 10 to 20 10 to20 1 Premix — — 40-50 40-50 — — 70-80 70-80 10 to 20 10 to 20 — — 2Premix 5 to 20 5 to 20  40-50 40-50 — — — — 80 to 90 80 to 90 80-9080-90 3 Thick- — 1 to 1.5 — 1 to 1.5 — 1 to 1.5 — 1 to 1.5 — 1 to 1.5 —1 to 1.5 ener Tacki- 20- 20-30 5 to 10 5 to 10  20-30*** 20-30 — 1 to1.5 — — — — fier 30** Cross- — — — — — — 1 to 2 1 to 2   1 to 2 1 to 2  1 to 2 1 to 2   linker Com- Adhe- Higher Results Higher High HigherLabel PSA Higher Various Higher Higher Higher ments sion to viscositymay viscosity adhesion/ viscosity having viscosity remova- viscosityadhesion vis- polyolefin coaters range coaters surface coaters shortterm coaters bility on coaters and cosity surfaces, from low dependentremova- different remova- coaters **range to ***range bility surfacesbility on will result moderate will re- leading to different in adhesionsult in permanent surfaces moderate for label moderate adhesion to highappli- to high adhesion cations adhesion

Example 3

[0076] Preparation of Caulk Premixes

[0077] The following premixes are useful for formulating a line ofcaulks.

[0078] A first binder premix contains a soft acrylic binder having a Tgof −50° C. (Rhoplex 1950, available from Rohm and Haas Company,Philadelphia, Pa.). The solids content of the binder is about 62-65% Thesoft acrylic binder is formulated with caulk additives well known tothose skilled in the art, such as glycols, surfactants, preservatives,mildewcides, defoamers, and optional additives, such as, silanes foradhesion.

[0079] A second binder premix contains a polymeric binder that is alower cost, vinyl or vinyl/acrylic binder having a Tg of −9° C. (Rovace86, available from Rohm and Haas Company, Philadelphia, Pa.) and solidscontent of about 55%. It is formulated into a lower cost premix by usinga plasticizer to further reduce the Tg and other caulk additives such asthose used in the above acrylic binder.

[0080] An extender premix is prepared by grinding calcium carbonate andtitanium dioxide in water with a dispersant and a thickener which areselected to produce a stable premix. This premix should be prepared atas high a solids content as possible to reduce the amount of waterintroduced into the caulk. The resulting caulk will shrink less whenused to fill a space. Because of this, solid pigment and or filler canbe utilized to further increase the solids of the caulk. The caulk willrequire mixing or milling techniques capable of handling its highviscosity.

[0081] An additive premix containing a solid-grade of hydroxy ethylcellulose (Natrosol 25OMXR, Hercules, Inc., Wilmington, Del.) isprepared for use as a thickener.

Example 4

[0082] Preparation of Caulks

[0083] A caulk is prepared by blending one or both the binder premixeswith the extender premix. The additive premix is then added and theresulting mixture is milled or mixed in an a Sigma mill or HockmeyerMixer (Hockmeyer Equipment Corp., Elizabeth City, N.C.). Optionally, themill or mixer can contain a feed screw that fills caulk tubes, thuscreating a continuous process for the production of the caulk. Utilizingthe method of the invention, this continuous production of caulks couldprovide a line of caulks on demand.

[0084] The four premixes described above are used to produce a line ofcaulks by combining them in different proportions. For example,utilizing the first binder premix, the extender premix, and additivepremix, a high quality caulk can be produced. Several grades of thiscaulk can be provided by using different amounts of the extender premix.In an analogous fashion, the second binder premix may be used to produceseveral lower quality/lower cost caulks. Further or alternativevariations in caulk quality and properties can be achieved by usingcombinations of the first and second binder premixes along with theextender premix, and the additive premix (i.e., thickener). Excludingthe extender premix produces a clear caulk. Using one or both of thebinder premixes results in a quality range of clear caulks.

[0085] Many variations of this example are possible. The filler andpigment can be provided in the form of separate premixes and their ratioand level can be controlled so that properties such as adhesion andsurface tack can be varied. Caulks with little or no titanium dioxidecan be tinted or colored with other pigments. Thickeners that requireneutralization with base can be utilized, including, for example, ahydrophobically-modified, alkali-swellable emulsion such as Acrysol™TT-615 (available from Rohm and Haas Company, Philadelphia, Pa.). Whensuch a thickener is used a base such as ammonium or sodium hydroxide maybe added during the mixing or milling of the caulk. Mixtures ofthickeners may be used. Many other caulk additives, such as fumedsilica, flash rust inhibitors, zinc complex, hindered amine lightstabilizers and the like may be employed in the various premixes.

What is claimed is:
 1. A set of different, but mutually compatible,fluid binder premixes sufficient to form at least one adhesive line, theset comprising: (i) at least one premix which comprises at least onepolymeric binder having a peel of less than about 20 ounces/inch; a tackof less than about 300 grams; and a shear of greater than about 50hours; (ii) at least one premix which comprises at least one polymericbinder having a peel of less than about 20 to about 50 ounces/inch, atack of about 300 to about 500 grams, and a shear of about 5 to about 50hours; and (iii) at least one premix which comprises at least onepolymeric binder having a peel of greater than about 50 ounces/inch, atack of greater than about 500 grams, and a shear of less than about 10hours.
 2. An adhesive comprising the set of premixes of claim 1 and atleast one additive selected from the group consisting of a tackifier, aplasticizer, a thickener, a crosslinker, and mixtures thereof.
 3. Theset of premixes of claim 1, wherein the number of premixes is from 3 to15.
 4. The set of premixes of claim 1, wherein at least one of thepremixes further comprises at least one additive selected from the groupconsisting of a tackifier, a plasticizer, a thickener, and acrosslinker.
 5. A method of forming at least one adhesive line, whichmethod comprises the steps of: (a) providing a set of different, butmutually compatible, fluid binder premixes which set comprises: (ii) atleast one premix, which comprises at least one polymeric binder having apeel of less than about 20 ounces/inch, a Polyken tack of less thanabout 300 grams, and a shear of greater than about 50 hours; (iii) atleast one premix which comprises at least one polymeric binder having apeel of less than 20 about 50 ounces/inch, a Polyken tack of about 300to about 500 grams, and a shear of about 5 to about 50 hours; and (iv)at least one premix which comprises at least one polymeric binder havinga peel of greater than about 50 ounces/inch, a Polyken tack of greaterthan about 500 grams, and a shear of less than about 10 hours; and (b)dispensing a predetermined amount of each of the premixes intocontainers or an applicator to form the adhesive line.
 6. A method offorming a range of adhesives, the range comprising at least two adhesivelines, which method comprises the steps of: (a) providing a set ofdifferent, but mutually compatible, fluid binder premixes, which setcomprises: (ii) at least one premix which comprises at least onepolymeric binder having a peel of less than about 20 ounces/inch, aPolyken tack of less than about 300 grams, and a shear of greater thanabout 50 hours; (iii) at least one premix which comprises at least onepolymeric binder having a peel of less than about 20 to about 50ounces/inch, a Polyken tack of about 300 to about 500 grams, and a shearof about 5 to about 50 hours; (iv) at least one binder premix whichcomprises at least one polymeric binder having a peel of greater thanabout 50 ounces/inch, a Polyken tack of greater than about 500 grams,and a shear of less than about 10 hours; and (v) at least one additionaldifferent binder premix selected from premixes (i) to (iii); and (b)dispensing a predetermined amount of each of the premixes intocontainers or applicators to form the adhesive lines.
 7. The method ofclaim 5 or claim 6, further comprising the step of providing at leastone additive selected from the group consisting of a tackifier, aplasticizer, a thickener, and a crosslinker.
 8. The method of claim 7,further comprising the step of dispensing predetermined amount(s) of theadditive(s) into the containers or the applicator.
 9. The method ofclaim 5 or claim 6, wherein at least one of the premixes furthercomprises at least one additive selected from the group consisting of atackifier, a plasticizer, a thickener, and a crosslinker.
 10. The methodof claim 5 or claim 6, wherein the number of premixes is from 4 to 15.11. A set of different, but mutually compatible, fluid binder premixessufficient to form at least one adhesive line, which set comprises atleast two premixes selected from the group consisting of: (a) at leastone premix comprising at least one prepolymer that forms a polymericbinder having a Tg of about −70° C. to about 0° C. when cured; (b) atleast one premix comprising at least one prepolymer that forms apolymeric binder having a Tg of about −10° C. to about 70° C. whencured; (c) at least one premix comprising at least one polymeric binderhaving a Tg of about 0° C. to about 30° C.; (d) at least one premixcomprising at least one polymeric binder having a Tg of about −15° C. toabout 15° C.; and (e) at least one premix comprising at least onepolymeric binder having a Tg of about −70° C. to about 0° C.
 12. Amethod of forming at least one adhesive line, which method comprises thesteps of: (a) providing the set of binder premixes of claim 11; and (b)dispensing a predetermined amount of each of the selected premises intocontainers or applicator to form the adhesive line.
 13. A method offorming a range of adhesives, the range comprising at least two adhesivelines, which method comprises the steps of: (a) providing a set of atleast three different, but mutually compatible, fluid binder premixeswhich are selected from the group consisting of: (i) at least one premixcomprising at least one prepolymer that forms a polymeric binder havinga Tg of about −70° to about 0° C. when cured; (ii) at least one premixcomprising at least one prepolymer that forms a polymic binder having aTg of about −10° C. to about 70° C. when cured; (iii) at least onepremix comprising at least one polymeric binder having a Tg of about 0°C. to about 30° C.; (iv) at least one premix comprising at least onepolymeric binder having a Tg of about −15° to about 15° C.; (v) at leastone premix comprising at least one polymeric binder having a Tg of about−70° C. to about 0° C.; and (vi) at least one additional differentpremix selected from the group consisting of premixes (i), (ii), (iii),(iv), and (v); and (b) dispensing a predetermined amount of each of theselected premixes into containers or applicators to form the adhesivelines.
 14. The method of claim 5, 6, 12 or 13, further comprising thestep of mixing the premixes before, while, or after the premixes aredispensed into the containers.
 15. The method of claim 5, 6, 12 or 13,further comprising the step of mixing the premixes before or while thepremixes are dispensed into the applicator(s).
 16. The method of claim5, 6, 12 or 13, further comprising the step of adjusting the viscosityof the premixes before, while, or after the premixes are dispensed intothe containers.
 17. The method of claim 5, 6, 12 or 13, furthercomprising the step of adjusting the viscosity of the premixes before orwhile the premixes are dispensed into the applicator(s).
 18. The methodof claim 5, 6, 12 or 13, wherein the method is carried out at amanufacturing facility.
 19. The method of claim 5, 6, 12 or 13, whereinthe method is carried out at a point-of-sale.
 20. The method of claim 5,6, 12 or 13, wherein the method is carried out at a point-of-use. 21.The method of claim 5, 6, 12 or 13, wherein the method is controlled bya computer.
 22. The method of claim 5, 6, 12 or 13, further comprisingthe step of providing at least one additive selected from the groupconsisting of a tackifier and a plasticizer.
 23. A set of different, butmutually compatible, fluid premixes sufficient to form at least onecaulk line, which set comprises: (i) at least one binder premixcomprising at least one polymeric binder having a Tg of less than about0° C.; (ii) at least one binder premix comprising at least one polymericbinder, having a Tg of less than about 25° C.; and (iii) optionally atleast one extender premix comprising at least one extender.
 24. The setof premixes of claim 23, which set further comprises at least oneadditional fluid binder premix or fluid extender premix.
 25. The set ofpremixes of claim 24, wherein the fluid extender premix furthercomprises at least one opacifying pigment.
 26. The set of premixes ofclaim 23, further comprising at least one fluid opacifying premixcomprising at least one opacifying pigment.
 27. A method of forming atleast one caulk line, which method comprises the steps of: (a) providingthe set of the premixes of claim 23, 24, 25 or 26; and (b) dispensing apredetermined amount of each of the selected premixes into containers orapplicator(s) to form the caulk line.
 28. The method of claim 27,wherein the method is continuous.
 29. The method of claim 27, furthercomprising the step of mixing the premixes before, while, or after theyare dispensed into the containers.
 30. The method of claim 27, furthercomprising the step of mixing the premixes before or while they aredispensed into the applicator(s).
 31. The method of claim 27, furthercomprising the step of adjusting the viscosity of the premixes before,while, or after they are dispensed into the containers.
 32. The methodof claim 27, further comprising the step of adjusting the viscosity ofthe premixes before or while they are dispensed into the applicator(s).33. The method of claim 27, wherein the method is carried out at amanufacturing facility.
 34. The method of claim 27, wherein the methodis carried out at a point-of-sale.
 35. The method of claim 27, whereinthe method is carried out at a point-of-use.
 36. The method of claim 27,wherein the method is controlled by a computer.